This invention relates to a wood preservative composition, process for treating wood with a wood preservative composition, and wood treated with a wood preservative composition.
As durable wood preservative composition conventionally, a water solution containing a metal compound and/or an inorganic compound has been used in a wide range for a long time. Such a solution is impregnated into wood to produce wood capable of keeping wood-attacking organisms from growing therein.
For example, the following compounds have been mainly used as preservative ingredients for wood preservative compositions; Copper compounds such as copper acetate, copper chromate; Chrome compounds such as potassium chromate, sodium dichromate; Mercury compounds such as mercury chloride; Arsenic compounds such as arsenious acid; Fluorine compounds such as sodium fluoride; and Boron compounds such as boric acid and borax. These compounds are mixed in a proper proportion and dissolved in water to produce a wood preservative solution.
In some cases, also, a fixing agent such as acetic acid or aqueous ammonia is added into the solution. When the solution containing such a fixing agent is impregnated into wood, chemical reactions between preservative ingredients, between a preservative ingredient and the fixing agent, and between a preservative ingredient and the wood take place, so that the preservative ingredient is fixed on the wood to ensure the wood preservative effect for a long period of time.
Especially, a combination of copper compound, chrome compound, and arsenic compound has been widely used as active preservative ingredients for a wood preservative composition. A solution containing these compounds has been called CCA preservative composition. Also, a combination of copper compound, chrome compound, and boric acid has been used as active preservative ingredients for a wood preservative composition. A solution containing these compounds has been called CCB preservative composition.
The CCA preservative composition and CCB preservative composition are comparatively cheap and have a long-time effectiveness. However, the arsenic compound is poisonous. Also, heavy metal compounds such as chrome and mercury have considerably high toxicity to warm-blooded animals.
Accordingly, severe attention has been necessary to pay to workers' health at the time of preparing such a preservative composition and treating wood with the preservative composition.
Also, in discarding unnecessary pieces of wood treated with such a preservative composition which inevitably are produced as by-product when the wood is cut into a desired form furniture made of wood treated with such a preservative composition, or building materials of wood treated with such a preservative composition, severe management has been required to prevent environmental pollution. Further, even if such scraps are burnt, toxic substances diffuse in the air or remain as ash for a long time and cause environmental problems.
Moreover, in addition to the problem of having high toxicity to warm-blooded animals, the CCB preservative composition has a problem that the boric acid is liable to be leached, which results in reduction of the preservative effectiveness.
To avoid the environmental pollution, use of organic metal compounds such as copper naphthenate, zinc naphthenate, or quaternary ammonium compounds has been proposed. However, these preservative ingredients have shorter-term effectiveness. Particularly, it has been impossible to employ these preservative ingredients for wood for building materials.
In view of the above-mentioned problems, a wood preservative composition has been desired which makes it possible to protect wood from wood attacking organisms for a prolonged period of time without involving environmental pollution. Also, eagerly have been desired a process for treating wood with a preservative composition capable of protecting wood from wood attacking organisms for a prolonged period of time without involving environmental pollution, and wood treated with a preservative composition capable of protecting wood from wood attacking organisms for a prolonged period of time without involving environmental pollution.
Accordingly, it is a first object of the present invention to provide a wood preservative composition which makes it possible to protect wood from wood attacking organisms for a prolonged period of time without involving environmental pollution.
Also, it is a second object of the present invention to provide a process for treating wood with a wood preservative composition capable of protecting wood from wood attacking organisms for a prolonged period of time without involving environmental pollution.
Further, it is a third object of the present invention to provide wood treated with a wood preservative composition capable of protecting wood from wood attacking organisms for a prolonged period of time without involving environmental pollution.
According to the present invention, a wood preservative composition comprises a preservative component which is selected from the group consisting of copper borate and zinc borate, a volatile basic compound of the formula R.sub.3 N, wherein R is one of a hydrogen atom and a lower alkyl group, and water.
According to the present invention, also, a process for preserving wood comprises the steps of impregnating wood with a wood preservative composition including a preservative component which is selected from the group consisting of copper borate and zinc borate, a volatile basic compound of the formula R.sub.3 N, wherein R is one of a hydrogen atom and a lower alkyl group, and water, and drying the impregnated wood to remove the volatile basic compound and water.
According to the present invention, further, a wood is produced by impregnating the wood with a wood preservative composition including a preservative component which is selected from the group consisting of copper borate and zinc borate, a volatile basic compound of the formula R.sub.3 N, wherein R is one of a hydrogen atom and a lower alkyl group and water, and drying the impregnated wood to remove the volatile basic compound and water.
The wood preservative composition of the present invention, which does not contain poisonous substances such as chrome compound and arsenic compound as in the CCA preservative composition, has the necessary anti-insect and anti-fungi effectiveness for a prolonged period of time without involving environmental pollution.
Also, the wood preservative composition of the present invention, which does not contain chrome compound and free boric acid as in the CCB preservative composition, has no toxicity to warm-blooded animals, and is not liable to be leached. Accordingly, the wood preservative composition can have the necessary anti-insect and anti-fungi effectiveness for a prolonged period of time.
Further, wood treated with the wood preservative composition of the present invention makes it possible to assure long use as safe wood materials for building, furniture, and the like.
These and other objects, features and advantages of the present invention will become more apparent upon a reading of the following detailed description.